What is Lactose Intolerance?

People who suffer from lactose intolerance have a lactase deficiency, which prevents them from fully digesting the milk sugar in dairy products. Lactase is an enzyme produced by the lining of your small intestine, and although many people have a low count of this enzyme, not all have a negative reaction when they eat dairy products. Only those who have a low level of lactase in their small intestine and show certain symptoms after eating dairy foods are considered lactose intolerant.

When the body doesn't have enough lactase, it allows most of the lactose in your food to move unprocessed into your colon. Your normal intestinal bacteria will then interact with the unprocessed lactose and cause symptoms common to lactose intolerance, such as diarrhea, gas, bloating, nausea, and abdominal pain. Symptoms typically begin 30 minutes to 2 hours after you eat foods that contain lactose.

Primary (results from aging) - your body produces a large amount of lactase during your early childhood, when milk is your primary source of nutrition. As you age, your diet relies less on milk and therefore your lactase production decreases. This decrease in lactase may lead to symptoms of lactose intolerance.
Secondary (results from illness or injury) - an injury, surgery, or illness of the small intestine could cause your body to produce less lactase. Illnesses that cause lactose intolerance include intestinal disorders such as celiac disease and gastroenteritis, and inflammatory bowel diseases like Crohn's disease. Although it may take some time, treatment of the underlying disorder can help restore your lactase levels and improve your symptoms.
Congenital (condition you're born with) - although rare, babies can be born lactose intolerant due to an absence of lactase activity in their bodies. This condition is inherited, and both the mother and father must pass on the defective form of the gene to the baby. The baby will exhibit symptoms like diarrhea after drinking his or her mother's breast milk.

If you or your child has symptoms of lactose intolerance, you may want to consult your physician. Your doctor may diagnose you based on your symptoms and your response to certain foods, however he or she may confirm the diagnosis by conducting a variety of tests. Unfortunately there aren't any medications you can take to boost your body's lactase production. People with lactose intolerance can minimize symptoms by decreasing the amount of dairy they consume, or by taking special products, such as lactase enzyme supplements, as a means of treatment for lactose intolerance.